Question

Iron carbonyl, \[{\text{Fe}}{\left( {{\text{CO}}} \right)_5}\] is:
A. Trinuclear
B. Mononuclear
C. Tetranuclear
D. Dinuclear

Answer 1

Hint: Here, we will proceed by defining the nuclearity of the coordinate compounds. Then draw the structural formula of Iron carbonyl \[{\text{Fe}}{\left( {{\text{CO}}} \right)_5}\] to find the nuclearity of the given coordinate compound.

Complete answer:
Definition of Nuclearity: The nuclearity of a single coordination entity indicates the number of central atoms joined by bridging ligands or metal-metal bonds.
The simplest nuclearity is mononuclear, followed by dinuclear, trinuclear, tetranuclear, pentanuclear…………………………., polynuclear.
Iron pentacarbonyl, also known as Iron carbonyl, is the compound with compound with formula \[{\text{Fe}}{\left( {{\text{CO}}} \right)_5}\].
The structural formula of Iron carbonyl \[{\text{Fe}}{\left( {{\text{CO}}} \right)_5}\] is:

From the structural form of Iron carbonyl \[{\text{Fe}}{\left( {{\text{CO}}} \right)_5}\], one Fe atom is surrounded by 5 CO ligands.

So, Iron carbonyl \[{\text{Fe}}{\left( {{\text{CO}}} \right)_5}\] is mononuclear.

Note: Under standard conditions \[{\text{Fe}}{\left( {{\text{CO}}} \right)_5}\] is a free-flowing, straw-coloured liquid with a pungent smell. Mononuclear complexes are the simplest types of coordination compounds that contain a single metal atom or ion surrounded by monodentate ligands.